Lieutenant Colonel Mayele, a commander of the Mai Mai "Cheka" militia group, one of the three armed movements involved in co-ordinated mass rape, was handed over today to UN peacekeepers and the Congolese army in Walikale, eastern Congo. He is in detention in the provincial capital Goma, where the Congolese military has opened a case against him.-

The extent of the rapes carried out by militiamen between 30 July and 2 August was shocking even by the horrific standards of eastern Congo. It also highlighted the impotency of the Congolese army and the UN force, known as Monusco, which is the world's largest peacekeeping mission.

Operating in concert, about 200 militiamen allied to Mai Mai "Cheka", the Democratic Forces for the Liberation of Rwanda (FDLR) and a third, smaller, armed group, took over 13 villages in the Kibua-Mpofi area of Walikale, one of the most insecure parts of eastern Congo.

Militiamen attacked the villages or waited in the surrounding forests for those who fled – while their comrades guarded a hillside position that offers the only mobile network coverage in the area, to prevent the alarm being raised. Over four days, at least 303 people were raped – 235 women, 52 girls, 13 men and 3 boys – according to a preliminary UN investigation published last month. Many of the victims were raped repeatedly.

"The scale and viciousness of these mass rapes defy belief," Navi Pillay, the UN high commissioner for human rights, said at the time.

The UN report said local people believed the attack was linked to the struggle to control lucrative mineral deposits in the area, with the affected villages considered by the militias to be pro-government.

Although a Monusco contingent was based less than 20 miles from where the rapes took place, the atrocities were not made public until an NGO raised the alarm three weeks later. The UN investigation said the failure by Congo's security forces to stop the attack was "compounded by subsequent failings" by Monusco forces, which lacked training and adequate communication systems.

After the rapes became public, the UN secretary general, Ban Ki-Moon, sent the deputy head of the his peacekeeping department, Atul Khare, to Congo to investigate. He also instructed Margot Wallström, the UN special representative for sexual violence in conflict, to take charge of the response. In a statement from Congo, Wallström called the arrest of Mayele a victory for justice. "The numerous criminal acts committed under 'Lt Col' Mayele's command cannot be undone, but let his apprehension be a signal to all perpetrators of sexual violence that impunity for these types of crimes is not accepted and that justice will prevail," she said.

Human rights activists welcomed the news but said it would not be a deterrent. Mayele is not considered a leading figure among the militias in eastern Congo, and would have only controlled some of the men who carried out the attack.=

The FDLR, which is led by Rwandan Hutus linked to the 1994 genocide, is considered the main impediment to peace in eastern Congo, and allegedly committed a further 214 rapes later in August, according to the UN.

"It would have made a bigger difference if they arrested the FDLR leaders who were involved in the first attack," said Fidel Bafilemba, a researcher in Goma for the Enough Project.